1 /* $NetBSD: kobj_rename.c,v 1.1 2010/04/26 23:17:13 pooka Exp $ */ 2 3 /*- 4 * Copyright (c) 2010 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: kobj_rename.c,v 1.1 2010/04/26 23:17:13 pooka Exp $"); 30 31 #define ELFSIZE ARCH_ELFSIZE 32 33 #include <sys/param.h> 34 #include <sys/exec_elf.h> 35 #include <sys/kmem.h> 36 #include <sys/kobj.h> 37 #include <sys/systm.h> 38 39 /* 40 * Mangle symbols into rump kernel namespace. This means 41 * putting "rumpns" in front of select symbols. 42 * See src/sys/rump/Makefile.rump for more details on the rump kernel 43 * namespace. 44 */ 45 const char *norentab[] = { 46 "RUMP", 47 "rump", 48 "__", 49 "_GLOBAL_OFFSET_TABLE", 50 }; 51 static int 52 norename(const char *name) 53 { 54 unsigned i; 55 56 for (i = 0; i < __arraycount(norentab); i++) { 57 if (strncmp(norentab[i], name, strlen(norentab[i])) == 0) 58 return 1; 59 } 60 return 0; 61 } 62 63 #define RUMPNS "rumpns_" 64 int 65 kobj_renamespace(Elf_Sym *symtab, size_t symcount, 66 char **strtab, size_t *strtabsz) 67 { 68 Elf_Sym *sym; 69 char *worktab, *newtab; 70 size_t worktabsz, worktabidx; 71 unsigned i; 72 const size_t prefixlen = strlen(RUMPNS); 73 74 #ifndef _RUMP_NATIVE_ABI 75 static int warned; 76 77 if (!warned) { 78 printf("warning: kernel ABI not supported on this arch\n"); 79 warned = 1; 80 } 81 #endif 82 83 /* allocate space for worst-case stringtab */ 84 worktabsz = *strtabsz + symcount * prefixlen; 85 worktab = kmem_alloc(worktabsz, KM_SLEEP); 86 87 /* now, adjust stringtab into temporary space */ 88 #define WORKTABP (worktab + worktabidx) 89 for (i = 0, worktabidx = 0; i < symcount; i++) { 90 const char *fromname; 91 92 sym = &symtab[i]; 93 if (sym->st_name == 0) { 94 continue; 95 } 96 97 fromname = *strtab + sym->st_name; 98 sym->st_name = worktabidx; 99 100 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL || 101 norename(fromname)) { 102 strcpy(WORKTABP, fromname); 103 worktabidx += strlen(fromname) + 1; 104 } else { 105 strcpy(WORKTABP, RUMPNS); 106 worktabidx += prefixlen; 107 strcpy(WORKTABP, fromname); 108 worktabidx += strlen(fromname) + 1; 109 } 110 KASSERT(worktabidx <= worktabsz); 111 } 112 #undef WORKTABP 113 114 /* 115 * Finally, free old strtab, allocate new one, and copy contents. 116 */ 117 kmem_free(*strtab, *strtabsz); 118 *strtab = NULL; /* marvin the paradroid 999 */ 119 newtab = kmem_alloc(worktabidx, KM_SLEEP); 120 memcpy(newtab, worktab, worktabidx); 121 122 kmem_free(worktab, worktabsz); 123 124 *strtab = newtab; 125 *strtabsz = worktabidx; 126 127 return 0; 128 } 129